Fire door



July 15, 1941- v A. A. ALLEN 2,249,591 v I J FIRE DooRl Filed Feb. 11, 1941 wavsrmxw INVENTOR ATTORNEY.

Patented July 15, 1941 FIRE DOOR Arthur A. Allen, Bellerose, N. Y., assigner to The Peele Company, Brooklyn, N. Y., a corporation of New York Application February 11, 1941,seria1No. 378,460

a claims. *Y (ci. ,2o-35) The invention relates to re doors, andino-re particularly to wooden cored metal sheathed doors.

It has long been the practice .toA equip door openings in Warehouses with closure means ,V

which, in many instances, consisted vof a movable door section or sectionshavingfan angle metal frame, the opening in which was closed by a .panel having a wooden'core protected by a metal sheathing so as to provide a reproof or .1',

fire retardant barrier at the door opening pre'- venting flame from passing from one side ofthe opening to the other side thereof.

Such doors have beenf-ound to be highly eiective in preventing the rapid spread of fire, par- ;L

ticularly by way'of the elevator shaft, from one oor to another in a building. When such doors are subjected to extremely high temperatures for a period of several hours, the heat, while insufficient to melt the metal of the sheathing, forms charcoal by distillation `of thewooden core and so warps and disrupts the metal sheathing as Ito permit the escape of charcoalv from within the metal sheathing. Such escape of charcoal becomes more rapid in case of the ``$`llJeI1ng of I seams of the sheathing. The escaper of awsubstantial amount of such charcoal permits direct application of heat at one side of the door to the other side Ithereof and may cause the disruption or breaking down of the sheathing upon both sides of the door and permit flames to pass through the door. p j v I have recently devised re vretardant building material of the type to which I have above referred, wherein excessive bulging vof the'metal sheathing is prevented by means of a strip of metal imbedded in the inflammable materialof the core enclosed by such sheathing, the edges of adjacent sheathing stripsy being secured inrrelation to the core by metal fasteners extending* through the sheathing on each side ,of the core and the imbedded metal strip, without, however, contacting or engaging the sheathing upon the other side, so as to prevent or minimize the conthe other side.

The present invention 'relates to a lire door structure utilizing the essential characteristics of building material of ythe character above ,referred to, so modied, however, as to adapt this material to use in varioustypes Iof doors in a manner to be hereinafter described. Y

In a door embodying the invention, one face duction lof heat from one side of the materialto vthereof may be more liable to be subjected to i Vthe heat of flames during a lire Ithan the other, and a door embodying the invention is so constructed as to oier the maximum resistancefto :distortion due lto high temperatures adjacent this face of the door.

\ In the event of a severe nre, the Wooden core of the door will almost inevitably be reducedto charcoal, and the purpose of the invention isnot ,to prevent the distillation of the wood ofthe core, but to permit such action of the heat While preventing the development of sufficient pressure ofV gases created by such distillation withinthe metal sheathing to cause excessive warping, bulging or displacement of any portion of the strips of the metal sheathing and a resultant escape or lshifting of'charcoal formed within the sheathing to an extent to materially impair the heat insulating properties of the door. p

This is done by venting of such gases at divergent points throughout the panel of a door section where they may escape or be consumed without introducing any additional re hazard about 'the door. The method employed in venting such'gases nei-ther accelerates nor retards distillation of the wood Aof the core, but l-does prevent the development of localizedV pressure spots-tending to distort the metalV sheathing or cause an opening of a seam between adjacent strips of metal of which said sheathing is formed.

-The construction is such as to permit a direct iiow of gases from within the sheathing to adjacent .theV face of .the door subjected to flame, the construction and arrangement, of parts being such as to so cover the vent openings as to avoid exposure of the inliammable material of the core and exclude ame from within the metal sheathing. A

In a'door embodying the' invention, Vthe provision for' venting of the gases developed by the heat of distillation during a iire may be limited to one sid-e -of the door. The other side of the door,

while provided with metal sheathing of the same v from within the sheathing at the face of the door which is subjected to the high temperatures, and is there consumed. While there may be slight bulging or distortion of the metal sheathing upon this side of the door, this has been found to be insufficient to cause any material disturbance of the charcoal filler, when such is formed, and the combined action of `the imbedded strip and the securing means between same and the edges of the strips of metal sheathing, and of the vent openings through the strips contiguous to the seam, have been found to prevent any such opening of the seam as will permit the escape of charcoal from Within the sheathing.

The invention consists primarily in a re door embodying therein a panel comprising a plurality of plies of inflammable material, a metal strip imbedded therein, a metal sheathing enclosing said core composed of a plurality of parallel strips of metal having a turned edge and a vent opening therethrough adjacent said edge, metal fasteners passing through said sheathing strips adjacent the edges thereof and an adjacent metal strip imbedded in the core, and ajflanged cap the flanges of which form a lap joint with the inturnededges of adjacent sheathing strips, said cap being of a width to cover the seam between adjacent sheathing strips and a vent opening adjacent said seam; and in such other novel features of construction and combination of parts as are hereinafter set forth and described, and more particularly pointed out in the claims hereto appended.

Referring to the drawing- Fig. 1 is an elevation of a portion of a section of van elevator door embodying the invention;

Fig. 2 is a section upon a larger scale, on the line 2-2 of Fig. l;

Fig. 3 is a view of a fragmentary portion thereof on the shaft side of a door adjacent one of the seams, broken away upon different planes; and

Fig. 4 is a detail sectional View of a fragmentary portion of the upper portion of the door section shown in Fig. 1 upon a larger scale.

Like numerals refer to like parts throughout the several views.

The structure of the door of the present invention hasto do with the enhancement of its fireproof or fire retardant properties, and in the accompanying drawing, only those characteristics contributing to this end are disclosed, other detalls old and well known in the art being omitted, particularly as such are capable of wide variation and have no bearing upon the present invention.

Referring to the drawing, a door section embodying the invention has an angle metal frame I0, the inwardly directed flange of which islocated upon the oor side of a door opening. The opening in this frame is closed by a panel including a core comprising, as shown in the accompanying drawing, two plies II and I2 of wood, usually about an inch in thickness, a sheet metalstrip or strips I3 imbedded in thisrcore by being positioned between the plies thereof, and an outer sheet metal sheathing which will be more fully described hereinafter.

This metal sheathing incloses the core of the panel closing the metal frame which, except for the metal strips I3, the sheathing and the means securing said sheathing in relation to said metal strips, is ordinarily of inflammable or combustible material, such as wooden planks as stated, and is therefore subject to destruction or deterioration by heat resulting from fire ,either the elevator shaft or upon any floor adjacent said shaft.

The metal sheathing upon each side of the door panel is made up of thin gauge sheet metal strips, ordinarily extending vertically of the door, such strips being indicated at I4, I5, I 6 and Il. The width and length of these strips will vary with different size doors. In Fig. l of the drawing, a door section having a height of about four feet and a width of about six feet is illustrated. The ends of each of these strips are turned over the top and bottom edges of the wooden ller of the core, the ends of the strips on opposite sides being folded in overlapping relation to each other, as shown in Fig. 4, and secured in any desired manner to the edges of the panel planks. The outer edges of the end strips are also folded in overlapping relation across the side edges of the panel planking. This is an old and well known construction in the type of door shown in the drawing.

It is customary, in wooden core, metal sheathed door sections, to secure the vertical edges of each of the strips by nails driven therethrough into the wood of the core, and to turn and fold the adjacent edges of adjacent stripsupon the strip, as shown at I8, so as to permit the formation of a lap joint between adjacent strips by means of a flanged cap strip I9 extending from top to bottom of the panel, the inturned flanges 2D of which cap strip interlock with the turned edges I8 of the adjacent sheathing strips.

This means of connecting the strips not only closes the seam between adjacent strips, but imparts a desirable nish to the door surface and excludes flame from any portion of the com-` bustible core which might otherwise be exposed at the seam.

In the embodiment of the invention shown in the drawing, the edges of adjacent sheathing strips are secured in relation to each other and to the core by means of metal fasteners, such as nails 2|, passing through the metal sheathing strips adjacent the edge thereof, through one of the plies of the core and through that metal strip I3 adjacent the edgesof these strips. These fasteners, however, are not of a length to engage the sheathing strip upon the opposite side of the panel, so that there is no means of direct transmission of heat from the metalv sheathingupon one side of the panel to the sheathing upon the other side thereof.

By this construction, however, the sheathing strips upon one side of the door are secured indirectly to sheathing strips upon the opposite side of the door. The securing means 2| act entirely independently of the Wood of the core to the extent that the relative position of parts is maintained even though the wood of the core be reduced to charcoal, which affords no grip for the nails or other securing members.

By the use of strips I3, any substantial displacement of the sheathing strips upon `one side of the panel in relation to those upon the other side is avoided, although some bulging or warping of the metal may occur in the presence of high temperatures. The amount of such, however, is small compared to previous constructions, and there is little or no tendency toward the opening .of seams between the edges of adjacent sheathing strips.

When a door is subjected to high temperatures, the wood of the core undergoes distillation and is converted into charcoal, the extent of this action being determined of course by the temperacharcoal.

During this action, gases are developed within the metal sheathing, and the construction is such as to avoid the formation of gas pockets and distortion of the sheathing by the pressure of the gas therein, while, at the same time, permitting the escape of these gases in a manner to avoid any increase of the fire hazard therefrom.

To secure the desired action, I provide the sheathing strip adjacent the turned edge thereof with one or more vent lopenings permitting gases to escape from within the panel between the lap joint and the outer surface of the sheathing strip Vhaving the opening therethrough. Such openranged substantially centrally of the height of the door and the others at equal distances above and below this opening. The width of these openings is such that the lap joint between the strips and the cap completely overlays the opening so as to not only conceal same, but prevent the flame from acting directly upon the wood through the vent openings.

With an arrangement as described, any gases within lthe metal sheathing of the door escaping through one or another of the numerous vent openings to between the cap I9 and the adjacent face of the door, will be discharged upon the side of the door, the sheathing upon which is provided with such vent openings.

By providing the vent opening in the sheathing beneath the lap joint securing adjacent strips of such sheathing together, and adjacent an intermediate strip I3, there is little or no obstruction to the flow of such gases, even though bulging of the sheathing strips is prevented, so that there can be no development of substantial pressure, irrespective of the extent of the destruction by distillation of the wood core. tion of the portion of the sheathing adjacent the seams between adjacent'sheathing strips, from gas pockets within the panel, is substantially prevented, or prevented to an extent to permit any substantial disturbance or displacement of the core or ller, even though it be reduced to charcoal. Obviously this condition will minimize likelihood of the escape of the granular material from within the sheathing in a manner to permit the heat upon one side of the door to act directly upon the other side thereof.

Ventopenings 22 may be provided only upon one side of the door, so that gases generated in the `event of ire are discharged into the flame and, even though they become ignited, they will f edge of the sheathing strip.

The width of the turned edge of the sheathing strips is suicient to substantially cover the vent openings, and the cap strip is of a width to ex- Hence, distortend across and cover the seam between adjacent 75 sheathing strips and all vent openings adjacent said seam. y

The various securing means 2l ordinarily consist of nails having twisted or serrated shanks to secure an effective anchorage between these nails and the imbedded strips I3.

The sheathing strips and the metal of the cap strip I9, in actual practice, are about fourteen gauge stock, although this dimension is exaggerated in the drawing.

When vent openings are provided in the sheathing upon only oneside'of the door, the other face of the door ordinarily is coated with asbestos or asbestos cement, indicated at 23, covering the entire face of the panel toward the inwardly directed flange, so as to minimize likelihood of excessive heat radiation from this face of the door, and, if desired, a supplemental metal facing sheet 24 may be secured at its edges to the inwardly directed flange of the frame, leaving an air gap between it and the non-iniiammable facing 23. This arrangement, while desirable, is not essential. It has been found, however, that with this arrangement, a temperature of '1700 or 1800 may be maintained upon one side of the door, and a temperature of less than 200 may be maintained upon the other side thereof.

The present invention is not directed broadly tothe manner of securing the sheathing upon opposite sides of a combustible core by means of a metal strip imbedded in the material of this core, but to a development in a door structure embodyingthis characteristic by which the eiectiveness of this securing means is increased by preventing the formation of gas pockets having pressure suflicient to distort the sheathing, particularly adjacent the securing means.

In a door embodying vthe invention, a number of divergent vent-openings may be provided, each of which will be covered at all times by the folded and turned edge of the sheathing strip and the flange and topof the cap strip.

In the event of the formation of gases within the sheathing, these gases, instead of being required to follow the tortuous path formed by the cap, its flange and the inturned edge of the strips, may escape directly to atmosphere beneath said parts. The material 'forming the lap joint may flex sufficiently to permit the free flow of such gases, but under no circumstances are the vent openings so exposed as to permit flame to act directly upon the core or permit charcoal to escape through the vent openings.

It is not myintention to limit the number, size or shape of the vent openings as herein shown and described, it being obvious that such may be varied with different doors.

It is essential, however, that the parts used in forming the lap joint upon opposite sides of a seamshall overlay such vent openings so as to close them against the escape of any part of the core and preventimpingement of flame upon the material of the core through the openings, and yet permit a direct flow of gases through such openings to about the adjacent face of the panel.

Having described the invention, what I claim Vas new and desire to have protected by Letters Patent, is:

l. A re door embodying therein a panel closing a door opening, said panel comprising a plurality 'of plies of` inflammable material, a metal strip Aimbedded therein, a metal sheathing enclosing said core composed of a plurality of parallel strips of metal having a turned edge and a vent opening therethrough adjacent said edge, metal fasteners passing through said sheathing strips adjacent the edges thereof and an adjacent metal strip imbedded in the core, and a flanged cap the flanges of which form a lap joint with the inturned edges of adjacent sheathing strips, said cap being of a Width to cover the seam between adjacent sheathing strips and a vent opening adjacent said seam.

2. A fire door embodying therein a panel closing a door opening, said panel comprising a plurality of plies of inammable material, a metal strip imbedded therein, a metal sheathing enclosing said core composed of a plurality of parallel strips of metal having a turned edge and a plurality of spaced vent openings therethrough adjacent said edge, metal fasteners passing through portions of said sheathing strips intermediate said openings, adjacent the edges thereof and an adjacent metal strip imbedded in the core, and a flanged cap the flanges of which form a lap joint with the inturned edges of adjacent sheathing strips, said cap being of a width to cover the seam between adjacent sheathing strips and all vent openings adjacent said seam.

3. A fire door embodying therein a panel closing a door opening, said panel comprising a plurality of plies of inflammable material, a plurality of metal strips imbedded therein at spaced intervals, a metal sheathing enclosing said core composed of a plurality of parallel strips of metal each having a turned edge and a plurality of vent openings therethrough adjacent said edge, metal fasteners passing through said sheathing strips respectively, adjacent the edges thereof and an adjacent metal strip imbedded in the core, and flanged caps the fianges of which form a lap joint with the inturned edges of adjacent sheathing strips, each of said caps being of a width to cover the seam between adjacent strips and a vent opening adjacent said seam.

4. A fire door embodying therein a panel closing a door opening, said panel comprising a plurality of plies of inflammable material, a plurality of metal strips imbedded therein at spaced intervals, a metal sheathing enclosing said core composed of a plurality of parallel strips of metal each having a turned edge and a plurality of spaced vent openings therethrough adjacent said edge, metal fasteners passing through portions of said sheathing strips intermediate said openings, adjacent the edges thereof and an adjacent metal strip imbedded in the core, and flanged caps the flanges of which form a lap joint with the inturned edges of adjacent sheathing strips, each of said caps being of a width to cover the seam between adjacent strips and all vent openings adjacent said seam.

5. A fire door embodying therein a panel closing a door opening, said panel comprising a plurality of plies of inflammable material, a metal strip imbedded therein, metal sheathing enclosing said core composed of a plurality of parallel strips of metal upon opposite faces of the panel, metal fasteners passing through said sheathing strips adjacent the edges thereof and the metal strip embodied in the core, a non-inflammable facing covering said sheathing upon one side of the panel, sheathing strips upon the other side of said door having turned edges and vent openings therethrough adjacent said edges, and a flanged cap the anges of which form a lap joint with the inturned edges of adjacent sheathing strips, said cap being of a width to cover the seam between adjacent sheathing strips and all vent openings adjacent said seam.

6. A fire door embodying therein an angle metal frame having an inwardly directed flange upon one side thereof, and a panel closing the opening in said frame, said panel comprising a plurality of plies of iniiammable material, a metal strip imbedded therein, metal sheathing enclosing said core composed of a plurality of parallel strips of metal upon opposite faces of the panel, metal fasteners passing through said sheathing strips adjacent the edges thereof and the metal strip embodied in the core, a non-inflammable facing covering said sheathing upon the side of the panel toward said inwardly directed flange, a metalv plate secured to the inwardly directed flange of said frame and forming an air gap between same and said facing, sheathing strips upon the other side of said door having turned edges and Vent openings therethrough adjacent said edges, and a flanged cap the flanges of which form a lap joint with the inturned edges of adjacent sheathing strips, said cap being of a width to cover the seam between adjacent sheathing strips and all bent openings adjacent said seam.

7. A fire door embodying therein a panel closing a door opening, said panel comprising a plurality of plies of infiammable material, a metal strip imbedded therein, metal sheathing enclosing said core composed of a plurality of parallel strips of metal upon opposite faces of the panel, metal fasteners passing through said sheathing strips adjacent the edges thereof and the metal strip embodied in the core, a non-inflammable facing covering said sheathing upon one side of the panel, sheathing strips upon the other side of said panel having turned edges and a plurality of spaced vent openings therethrough adjacent said edges, said metal fasteners passing through said sheathing strips intermediate said openings, and a flanged cap the anges of which form a lap joint with the inturned edges of adjacent sheathing strips, said cap being of a Width to cover the seam between adjacent sheathing strips and all bent openings adjacent said seam.

8. A fire door embodying therein a panel closing a door opening, said panel comprising a plurality of plies of indammable material, a plurality of metal strips imbedded therein at spaced intervals, metal sheathing enclosing said core composed of a plurality of parallel strips of metal upon opposite faces of the panel, metal fasteners passing through said sheathing strips adjacent the edges thereof and the metal strip embodied in the core, a non-infiammable facing covering said sheathing upon one side of the panel, sheathing strips upon the other side of said door, each having turned edges and a' plurality of spaced vent openings therethrough adjacent said edges, and flanged caps the flanges of which form a lap joint with the inturned edges of adjacent sheathing strips, said caps being of a width to cover the seam between adjacent sheathing strips and all vent openings adjacent said seam.

9. A lire door embodying therein an angle metal frame having an inwardly directed flange upon one side thereof, and a panel closing the opening in said frame, said panel comprising a plurality of plies of inflammable material, a plurality of metal strips imbedded therein at spaced intervals, metal sheathing enclosing said core composed of a plurality of parallel strips of metal upon opposite faces of the panel, metal fasteners passing through said sheathing strips adjacent the edges thereof and the metal strip embodied in the core, a non-inflammable facing covering said sheathing upon the side of the panel toward said inwardly directed flanges, a metal plate secured to the inwardly directed flanges of said frame and forming an air gap between same and said facing, sheathing strips upon the other side of said door, each having turned edges and a plurality of spaced ven-t openings therethrough adjacent said edges, and flanged caps the flanges of which form a lap joint with the inturned edges of adjacent sheathing strips, said caps being of a width to cover the seam between adjacent sheathing strips and al1 vent openings adjacent said seam.

ARTHUR A. ALLEN. 

